In contemporary society, we live and act within institutions. Institutions are understood here broadly as behavioural regularities in social interaction, which may result from people following formal or informal rules, explicit or tacit norms, or even taken-for-granted ways of acting in society. Understood broadly in this way, as many sociologists, anthropologists, political scientists, and economists do, social institutions are ubiquitous. When we buy and sell, learn and teach, or even simply socialize, our behaviours take place within social institutional frameworks of one kind or another. Despite the obvious implications of institutions for how one should act and live, and the importance accorded them in other human sciences, social psychology's engagement with institutions has been fragmented. In an attempt to orient a coherent approach, this chapter develops a social psychological perspective on institutions, discusses existing relevant psychological research in this perspective, and explores the implications of this perspective for future research.